Low-GWP refrigerants have been recently developed to suppress the influence of global warming. Conventionally used R410A is a refrigerant with good performance but has a GWP (global warming potential) of about 2000. Thus, R410A has been replaced with R32 having a GWP one third that of R410. R32 is a good-performance refrigerant with physical properties relatively similar to those of R410A and has a GWP of about 600. To achieve lower GWPs, fluoropropene (HFO) refrigerants such as R1234yf have been developed. However, such a refrigerant has a high boiling point with low performance and thus keeping the same performance as that of the related art may cause many technical problems resulting in high cost.
Accordingly, a refrigeration cycle apparatus has been proposed in which a low-GWP refrigerant (e.g., HFO1123) having a low boiling point is used (See Patent Literature 1).
It is known that HFO1123 (low boiling temperature refrigerant) having good performance (capability) less affects the ozone layer since chlorine atoms are not included in the composition and less affects global warming since it has a double bond and short atmospheric lifetime. Moreover, the combustion is classified as rank 2L (low flammability) by ASHRAE, achieving safety.
Furthermore, even mixed refrigerant of HFO1123 and refrigerants such as HO, HFC, HCFO, CFO, and HFO can partially achieve the advantage.